DEFINITION DEGREE. 



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themselves. A position before the defile, for the pur 

 pose of defending it, is only to be thought of when 

 the passage of another division is to be covered 

 This method may be more or less varied in the de 

 fence of bridges. In passing a defile in sight of the 

 enemy, after the usual precautions of patrols, &c. 

 the van-guard must first march rapidly through, anc 

 take a position before the outlet, so as to cover the de 

 velopment of the succeeding masses, the preventing 

 of which will be the object of the enemy. To defile 

 is, therefore, to pass through a narrow passage. To 

 march before any one with a narrow front, that is 

 en colonne, or by files, is also called defiling. 



DEFINITION (from the Latin definitio) of a thing 

 signifies, in lexicography, a concise account of its es- 

 sential and characteristic points. A definition shoulc 

 embrace all the essential properties of the object in- 

 tended to be defined, and not admit any which do not 

 belong to it, which is often extremely difficult, on 

 account of the shades and gradations by which dif- 

 ferent things are blended. A strictly accurate defi- 

 nition can be given of only a few objects. The most 

 simple things are the least capable of definition, from 

 the difficulty of finding terms more simple and intelli- 

 gible than the one to be defined. Of course, every 

 large dictionary abounds with definitions which ex- 

 plain nothing, since the thing defined cannot be made 

 clearer by any definition. A good definition must 

 give the mark of the genus (nota generate sen genus] 

 and of the species (nota specialis seu differentia spe- 

 cified) ; for instance, a barn is a building (nota genera- 

 lis) for the purpose of preserving corn, &c. (nota spe- 

 cialis). A definition may be analytic or synthetic. 



DEFLAGRATION, and DEFLAGRATOR. See 

 Galvanism. 



DEFLECTION OF THE RAYS OF LIGHT is 

 a property which doctor Hooke observed in 1674 5. 

 He says he found it different from both reflection and 

 refraction, and that it took place towards the surface 

 of the opacous body perpendicularly. This is the 

 same property which Newton calls inflection. It is 

 called, by others, diffraction. 



DEFOE, DANIEL, a writer of great ingenuity and fer- 

 tility, was born at London in 1663. His father's name 

 was simply Foe. He received his education at an aca- 

 demy at Newington Green, and he is not supposed to 

 have attained to much classical acquirement. He com- 

 menced author at the age of twenty-one, by a Treatise 

 against the Turks, joined the insurrection of the duke 

 of Monmouth, and had the good fortune to escape to 

 London, where he engaged first as a horse-factor, and 

 then as a maker of bricks at Tilbury fort. His com- 

 mercial speculations, however, failing, he became insol- 

 vent ; and it is to his credit, that, having cleared his 

 debts by a composition, he subsequently paid most of 

 them in full, when his circumstances were amended. 

 In 1697, he wrote an Essay on Projects. In 1701, 

 appeared his satire, The True-born Englishman, the 

 object of which was to show the folly of the popular 

 objection to king William, as a foreigner, by a peo- 

 ple who were themselves a mixture or so many races. 

 In 1702, when the high church party seemed dis- 

 posed to carry matters strongly against the dissen- 

 ters, he published The Shortest Way with the Dissen- 

 ters, being an ironical recommendation of persecution, 

 so gravely covered that many persons were deceived 

 by it. It was, however, voted a seditious libel by 

 the house of commons ; and the author avowing hi in- 

 self, to secure his printer and publisher, he was pro- 

 secuted to conviction, and sentenced to fine, imprison- 

 ment, and the pillory. He underwent the latter pun- 

 ishment with great equanimity, and was so far from 

 being ashamed of it, that he wrote a Hymn to the 

 Pillory, alluding to this circumstance. In February, 

 1703, while in Newgate he commenced the Review 



which is supposed to have given Steele the hint for his 

 Tatler. He was at length liberated from Newgate by 

 the interposition of Harley ; and the queen herself 

 sent money to his wife and family. In 1706, he pub- 

 lished his largest poem, entitled Jure Divino, a satire 

 on the doctrine of divine right. When the accession 

 of the house of Hanover became an interesting to- 

 pic, he wrote in its favour ; but so obtuse was the 

 public to his irony, that he was imprisoned for his 

 productions as libels in favour of the pretender. The 

 accession of George I. produced him no further pa- 

 tronage, and he began another line of composition. 

 In 1715, he published The Family Instructor, a work 

 inculcating moral and religious duties in a lively man- 

 ner, by narration and dialogue. To this work his 

 well known Religious Courtship, published in 1722, 

 formed a third volume. In 1719, appeared the most 

 popular of all his performances The Life and Surpris- 

 ing Adventures of Robinson Crusoe, the favourable 

 reception of which was immediate and universal. The 

 success of Defoe in this performance induced him to 

 write a number of other lives and adventures in cha- 

 racter ; as Moll Flanders, Captain Singleton, Roxa- 

 lana, Duncan Campbell, and The Adventures of a 

 Cavalier. In 1722, he published a Journal of the 

 Plague in 1665, in the person of a citizen supposed 

 to have been a witness of it. The natural manner in 

 which it is written deceived the celebrated doctor 

 Mead, who thought it genuine. In 1724, he publish- 

 ed the Great Law of Subordination, and, in 1726, his 

 Political History of the Devil, to which he afterwards 

 added, in the same style of reasoning, wit, and ridi- 

 cule, a System of Magic. He is also author of a 

 Tour through the Island of Great Britain, the Com . 

 plete English Tradesman, a Plan of English Com- 

 merce, and various other productions. He died in 

 April, 1731. A work has been lately published, 

 called Memoirs of the Life and Times of Daniel 

 Defoe, by Walter Wilson, three volumes, London. 

 1830. 



DEFTERDAR, in the Turkish empire; the min- 

 ister of the finances, and high treasurer of the em- 

 pire. It is to be observed that he is different from 

 the kasnadar-laschi, the treasurer of the sultan's 

 private purse. 



DEGRADATION. The ecclesiastical censure, 

 by which a clergyman is divested of his holy orders 

 is termed degradation. The ceremony consists chief- 

 ly in stripping off his clerical vestments. Geliot, in 

 his Indice Armoriel, describes the degradation of 

 Franget, a Gascon captain, for surrendering Fonta- 

 rabia under Francis I. The accusation of treason 

 was pronounced before twenty or thirty cavaliers. 

 The culprit was armed at all points, and his shield, 

 reversed, was suspended on a stake before him. By 

 his side, twelve priests chanted the vigils of the 

 dead. At the pause after each psalm, the officers 

 stripped the knight of a piece of his armour, till he 

 was quite bare. His shield was then broken in three 

 pieces, and the king.at arms poured a.basin of hot 

 water on his head. The criminal was afterwards let 

 down from the scaffold, by ropes under his arms, 

 and, being placed on a bier, covered with grave 

 clothes, and preceded by a priest chanting a mass 

 for the dead, was delivered to the civil judge and the 

 executioner. His life, however, eventually was 

 spared, since life, under such circumstances, was con- 

 sidered more bitter than death. 



DEGREE, in algebra, a term applied to equations, 

 ,o distinguish the highest power of the unknown 

 quantity. Thus, if the index of that power be three 

 or four, the equation is respectively of the third or 

 burth degree. 



DEGREE, in geometry or trigonometry, is the 

 360th part of the circumference ofany circle ; every 



